CTS, DCD, DSR, DTR, GND, PG, RI, RTR, RTS, RxD, TxD (alphabetically) makes around 11, I think.

chillingeffect 5 days ago | parent | next [-]

Plus the differential versions of most of those signals for long distance doubles the number of pins. And they have optional synchronous clocks. I did some WAN work for 3Com back in the day... :)

	▲	cestith 14 hours ago \| parent [-]
		A few devices back in the day could be powered over DB-25 connections besides the communications, even. Some in factories might still be.

▲

II2II 5 days ago | parent | prev | next [-]

If I recall correctly, the DB-25 RS-232 cables also facilitated two serial connections.

	▲	kps 5 days ago \| parent [-]
		You do. (I've never seen that used, though.)

▲

raverbashing 5 days ago | parent | prev [-]

Yes and then we came up with soft flow control for the win